Modern computer systems store data in devices or components internally or externally for later usage. There are various types of storage devices for which the computer systems could read/write data from/to the devices. One of the most widely used devices for storing massive amount of data in a computer system is a disc drive having a DSA.
The capacity of a disc drive depends on the numbers of tracks on the surface of the disc. When more tracks are formatted on a disc, the precision at which the transducer could read from or write to the disc becomes critical. There are a number of reasons that could cause the reading/writing process to be inaccurate, for example, imbalance of the disc drive, etc. Imbalance of a disc drive may be caused by the uneven distribution of mass about the axis of rotation of the DSA. Such imbalance may be the result of the disc shifting in a radial direction, sometimes known as “disc slip”, which in turn may cause inaccurate positioning of the transducer. When the number of tracks on the disc greatly increase, any imprecise positioning of the transducer becomes more critical to the overall performance of the disc drive.
There are a number of ways to reduce the imbalance of the DSA in a disc drive. For example, by biasing the disc(s) and spacer(s) in opposite directions with reference to the center of the motor shaft, and thereby having substantially equal mass distributed around the motor shaft longitudinal axis. While various devices and methods may be known for balancing a DSA, it is a continuous challenge to reduce the number of components and to simplify the steps in assembly so as to achieve greater manufacturing efficiency.
The present invention provides a solution to reduce the instability of the disc drive and at the same time reduces the use of spacers and/or balancing rings so as to cut down the production cost, and also provides other advantages over the prior art.